The share model defined in tree_shares.v can be extracted
to executable O'Caml code for use in tools.  The extracted
code is the executable slice of of the module "Share"
from the file "tree_shares.v".  The module type
is "SHARE_MODEL" defined in file "boolean_alg.v"

The exposed interface is essentially the boolean algebra
operators together with an equality test and some operations
to split shares and perform the token factory operations.
The extraction process will also produces to extraneous
methods "sa" and "saf", which are proof artifacts that
are incorrectly identified as computational.  They can
be ignored.

To generate the compilable O'Caml code type "make extract".
This should produce two files "tree_shares.mli" and
"tree_shares.ml".  These files can be directly
included in your O'Caml project.
